ASHRAE 90.1-1989
Regulatory requirements:
Since
NFRC did not publish standards before 1992, there are no reference
standards for thermal performance ratings for fenestration products.
Prescriptive
Requirements
The Prescriptive
Building Envelope Option establishes maximum requirements for
U-value and Shading Coefficient. These requirements are based
on local climate (heating and cooling degree days) and building
orientation. Glazing area is limited to 15% of the overall square
footage of the buildings If a building has greater than 15% glazing
area) another compliance path must be used (i.e., the Energy Cost
Budget Method).
System
or Design Requirements
The system
or design requirements are in ASHRAE 90.1 is outlined in the Energy
Cost Budget Method. It is used to evaluate the compliance of proposed
building designs and is intended for use with simulation programs
that model building efficiency. The models must report energy
usage by lights, internal equipment loads, and service water heating
equipment, space cooling and heat rejection equipment, fans and
other HVAC equipment. Using this approach, architects, builders,
and designers can increase the use of glass in buildings by utilizing
higher performance glass.
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